Subject: [PATCH]: fix queue limits in multiple qdiscs

From: Patrick McHardy <[email-masked]>
Date: Thu, 13 Nov 2003 15:50:21 +0100

This patch fixes multiple qdiscs exceeding their limits:

pfifo/pfifo_fast: by one packet
bfifo/red/gred: by one full-sized packet in bytes

RED and GRED should never reach their limits so this part is
more cosmetic than fix.

Best regards,
Patrick

# This is a BitKeeper generated patch for the following project:
# Project Name: Linux kernel tree
# This patch format is intended for GNU patch command version 2.5 or higher.
# This patch includes the following deltas:
#	           ChangeSet	1.1431  -> 1.1432 
#	net/sched/sch_generic.c	1.9     -> 1.10   
#	net/sched/sch_teql.c	1.8     -> 1.9    
#	net/sched/sch_fifo.c	1.6     -> 1.7    
#	net/sched/sch_gred.c	1.12    -> 1.13   
#	 net/sched/sch_red.c	1.8     -> 1.9    
#
# The following is the BitKeeper ChangeSet Log
# --------------------------------------------
# 03/11/12	[email-masked]	1.1432
# Fix queue limits in multiple qdiscs
# --------------------------------------------
#
diff -Nru a/net/sched/sch_fifo.c b/net/sched/sch_fifo.c
--- a/net/sched/sch_fifo.c	Thu Nov 13 15:23:33 2003
+++ b/net/sched/sch_fifo.c	Thu Nov 13 15:23:33 2003
@@ -47,7 +47,7 @@
 {
 	struct fifo_sched_data *q = (struct fifo_sched_data *)sch->data;
 
-	if (sch->stats.backlog <= q->limit) {
+	if (sch->stats.backlog + skb->len <= q->limit) {
 		__skb_queue_tail(&sch->q, skb);
 		sch->stats.backlog += skb->len;
 		sch->stats.bytes += skb->len;
@@ -108,7 +108,7 @@
 {
 	struct fifo_sched_data *q = (struct fifo_sched_data *)sch->data;
 
-	if (sch->q.qlen <= q->limit) {
+	if (sch->q.qlen < q->limit) {
 		__skb_queue_tail(&sch->q, skb);
 		sch->stats.bytes += skb->len;
 		sch->stats.packets++;
diff -Nru a/net/sched/sch_generic.c b/net/sched/sch_generic.c
--- a/net/sched/sch_generic.c	Thu Nov 13 15:23:33 2003
+++ b/net/sched/sch_generic.c	Thu Nov 13 15:23:33 2003
@@ -275,7 +275,7 @@
 	list = ((struct sk_buff_head*)qdisc->data) +
 		prio2band[skb->priority&TC_PRIO_MAX];
 
-	if (list->qlen <= qdisc->dev->tx_queue_len) {
+	if (list->qlen < qdisc->dev->tx_queue_len) {
 		__skb_queue_tail(list, skb);
 		qdisc->q.qlen++;
 		qdisc->stats.bytes += skb->len;
diff -Nru a/net/sched/sch_gred.c b/net/sched/sch_gred.c
--- a/net/sched/sch_gred.c	Thu Nov 13 15:23:33 2003
+++ b/net/sched/sch_gred.c	Thu Nov 13 15:23:33 2003
@@ -110,7 +110,7 @@
 	unsigned long	qave=0;	
 	int i=0;
 
-	if (!t->initd && skb_queue_len(&sch->q) <= sch->dev->tx_queue_len) {
+	if (!t->initd && skb_queue_len(&sch->q) < sch->dev->tx_queue_len) {
 		D2PRINTK("NO GRED Queues setup yet! Enqueued anyway\n");
 		goto do_enqueue;
 	}
@@ -175,7 +175,7 @@
 	if ((q->qave+qave) < q->qth_min) {
 		q->qcount = -1;
 enqueue:
-		if (q->backlog <= q->limit) {
+		if (q->backlog + skb->len <= q->limit) {
 			q->backlog += skb->len;
 do_enqueue:
 			__skb_queue_tail(&sch->q, skb);
diff -Nru a/net/sched/sch_red.c b/net/sched/sch_red.c
--- a/net/sched/sch_red.c	Thu Nov 13 15:23:33 2003
+++ b/net/sched/sch_red.c	Thu Nov 13 15:23:33 2003
@@ -257,7 +257,7 @@
 	if (q->qave < q->qth_min) {
 		q->qcount = -1;
 enqueue:
-		if (sch->stats.backlog <= q->limit) {
+		if (sch->stats.backlog + skb->len <= q->limit) {
 			__skb_queue_tail(&sch->q, skb);
 			sch->stats.backlog += skb->len;
 			sch->stats.bytes += skb->len;